Generally, a fastening device for connecting a printed circuit board with a fixed body includes a nut having an axial threaded bore and an end functioning as an inserting head. When using the nut to connect the printed circuit board with the fixed body, a layer of solder paste is first applied over a fixing hole on the printed circuit board. Then, the inserting head at one end of the nut is placed in the fixing hole on the printed circuit board, so that the inserting head along with the solder paste is fixed in the fixing hole. Thereafter, the fixed body is connected to the printed circuit board by threading a screw into the axial threaded bore from the other end of the nut.
While the above-described conventional fastening device is able to connect the printed circuit board with the fixed body, the axial threaded bore of the nut is not provided with any blocker. Therefore, when the inserting head of the nut is placed in the fixing hole on the printed circuit board and welded thereto, the solder paste applied over the fixing hole tends to enter into the axial threaded bore of the nut when the solder paste is compressed by a rear end of the inserting head and an adsorption effect occurs between an outer plated layer of the nut and a solder bonding layer. As a result, when the screw is screwed into the axial threaded bore of the nut, the screw would be interfered by the solder paste in the axial threaded bore and could not be successfully tightened to the nut, making it inconvenient to connect the printed circuit board with the fixed body.